Failure Case Library

Real lab failures, root causes, and fixes — curated and bilingually annotated by our team.

All Techniques (7) PCR (Sigma Guide) (12) End-point PCR Primers (9) Western Blot (9) Wound Healing Assay (5) Cell Culture (Contamination) (7) Lipid Transfection (8) CCK-8 Cell Viability Assay (5) Colony Formation Assay (10) Transfection (8) Nucleic Acid Quantification (9) Transfection (Co-transfection) (1) Protein Extraction (4) Plasmid Construction (Double Digest) (1) Sanger Sequencing (2) Plasmid Construction (1) qPCR (RT-qPCR) (5) Transwell Migration / Invasion Assay (5) Immunohistochemistry (IHC) (6) PCR (Polymerase Chain Reaction) (26) Restriction Enzyme Digest (13) DNA Cleanup & Plasmid Purification (7) RNA Cleanup (4) NGS Library Preparation (NEBNext Ultra II) (7) HMW DNA Extraction (Monarch) (7) LAMP (Loop-mediated Isothermal Amplification) (7) RNA Depletion for RNA-seq (7) Bacterial rRNA Depletion (4) Cell-free DNA Extraction (8) ELISA (Competitive) (18) ELISA (Signal Problems) (11) ELISA (High Background) (8) ELISA (Inconsistent Results / High CV) (6) ELISA (Standard Curve Fit Problems) (6) Western Blot (Weak / No Signal) (6) Western Blot (Detection Problems) (7) Western Blot (Bands at Wrong MW) (5) Western Blot (Misshapen / Uneven Bands) (5) Western Blot (Unexpected Multiple Bands) (7) Western Blot (Unusual Gel Band Appearance) (3) ChIP (High Background) (1) ChIP (Low Resolution with High Background) (6) ChIP (Low Signal) (8) ChIP (PCR Amplification Problems) (4) Immunohistochemistry (High Background) (9) Immunohistochemistry (No Staining) (9) Immunoprecipitation (High Antibody Elution) (1) Immunoprecipitation (High Background) (8) Immunoprecipitation (No Protein Detected) (5) Immunoprecipitation (Protein Obstruction) (1) ELISPOT (8) Tissue Imaging (Autofluorescence) (9) Flow Cytometry (Troubleshooting) (8) ELISA Development (9) Flow Cytometry (Autofluorescence) (7) Flow Cytometry (Compensation) (7) Flow Cytometry (Fc Blocking) (7) Flow Cytometry (Fixation & Permeabilization) (9) Flow Cytometry (Isotype Controls) (7) Flow Cytometry (Fixation Buffers) (7) Western Blot (CST Guide) (8) ChIP (CST Guide) (8) Immunoprecipitation (CST Guide) (14) Immunohistochemistry (CST Guide) (14) Flow Cytometry (CST Guide) (8) ELISA (R&D Guide) (10) ELISA (Sigma Guide) (6) Western Blot Immunodetection (19) IP-Western Blot (6) Flow Cytometry (Sample Considerations) (14) Flow Cytometry (Paraformaldehyde Fixation) (14) Western Blot (Sigma Protocol) (8) PCR / RT-PCR Amplification Problems (5) Cell Culture (Cell Death) (8) Cell Culture (Precipitates) (6) PCR (Invitrogen Guide) (8) PCR / qPCR Plastics (9) Flow Cytometry (Controls) (8) Plasmid Mini-prep (1) Transfection (siRNA Knockdown) (1) Western Blot (Blue Background) (1)
DNA Cleanup & Plasmid Purification critical

No DNA Recovered from Plasmid Miniprep

No detectable plasmid DNA is recovered after miniprep purification. Column elution yields no nucleic acid by spectrophotometry or gel electrophoresis.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification severe

Low Plasmid Yield Due to Incomplete Lysis

Plasmid miniprep yields are significantly below expected levels. A260/280 ratio may be normal but total DNA concentration is low.

💡 5 causes ✓ 5 fixes
DNA Cleanup & Plasmid Purification moderate

Low DNA Yield from Gel Extraction or PCR Cleanup Due to Incomplete Elution

DNA recovery from gel extraction or PCR cleanup is lower than expected based on input amount. Some DNA likely remains bound to column.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification severe

Low Gel Extraction Yield Due to Improper Gel Dissolution

DNA yield from gel extraction is poor. Undissolved agarose particles may be visible or column flow is impeded.

💡 4 causes ✓ 4 fixes
DNA Cleanup & Plasmid Purification critical

No DNA Recovered from Gel Extraction or PCR Cleanup

No DNA is recovered after gel extraction or PCR cleanup procedures. Elution yields no measurable nucleic acid.

💡 3 causes ✓ 3 fixes
DNA Cleanup & Plasmid Purification severe

Low Plasmid Quality Due to Degradation or Denaturation

Plasmid DNA shows smearing on gel, poor A260/280 ratio, or fails in downstream applications despite adequate concentration. Multiple bands or reduced supercoiled form may be visible.

💡 5 causes ✓ 5 fixes
DNA Cleanup & Plasmid Purification moderate

Low DNA Performance in Downstream Applications Due to Contaminants

Purified DNA fails or performs poorly in downstream applications (transformation, restriction digestion, PCR, sequencing) despite acceptable concentration and A260/280 ratio.

💡 6 causes ✓ 6 fixes